Temporary atrial standstill is a relatively rare event requiring intraatrial electrogram recordings for its documentation. Previous reports have emphasized its relationship to drug intoxication, infarction, the immediate post open-heart surgery period, or the premorbid state; significant impairment of atrial excitability is usual. The occurrence of atrial standstill in the presence of intact atrial excitability suggests "electrical isolation" of the atria. The three patients we describe manifested temporary atrial standstill while maintaining atrial excitability. Diffuse conduction system disease and drug effects played a contributory role.